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Re: (meteorobs) telescopic/binocular meteors by video recording

>      Conventional wisdom suggest we forget about the narrow FOV of
> scope and settle with just our naked eye / wide angle camera lens.  
> I just wonder whether it is still useful for at least some of us to
> attempt videotaping through low lux ccd with ~10 degree Fov using
> NAMN telescopic guide line - chosing two fields not very far from
> radian?

Sirko might wish to answer this. 

My opinion is that if you two systems operating use with a wide-angle
lens (hence smaller aperture) for visual meteors, and a larger lens,
smaller field to concentrate on telescopic magnitudes.  If you just have
one system, and a choice of lens, the choice is up to you.  The
wide-angle will be more impressive to show your friends.  The higher
magnification gives you more-accurate paths. 

If you have a low-light video system, it's worth trying it.  My advice
is to test it ahead of the Leonids, so you can iron out
technical problems.  You can of course do simultaneous visual or
telescopic observations while your video is operating.

>      Is there a way to figure out what is the expected # of meteors say
> within x degree FOV? Is there any published data to show the 'density'
> of meteors (# per degree diameter)  by magnitude.

It's not just FOV.  Just like for visual observing, the limiting
magnitude matters.   Factors which control the field of view are the
focal length of the lens and the diameter/size of the phosphor/chip.
Factors which affect the limiting magnitude include the focal
ratio and quality of the lens, the gain and noise of the intensifier,
the quantum efficiency of the chip (what fraction of the incoming
photons are detected), the quality of your site, the time of day
and year.

Perhaps you can see where this is leading.  I don't think there is a
magic formula to give you an answer.  Video is still comparatively in
its infancy.  You can get some idea reading reports such as Sirko's
monthly figures or from consulting articles listed at

  http://www.imodot net/video/

At home I do have an article by Bob Hawkes which does list some
figures such as typical FOVs and corresponding limiting magnitudes.

Malcolm

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